The Coastal Salinity Index (CSI) utilizes salinity data to characterize saline (drought) and freshwater (wet) conditions in coastal areas. The CSI is site-specific and can be computed for multiple time intervals from 1- to 24-months, to help users evaluate response to monthly (and longer) precipitation and streamflow conditions. The Coastal Salinity Index (CSI) was developed to characterize coastal drought, monitor changing salinity conditions, and improve understanding of the effects of changing salinities on fresh and saltwater ecosystems, fish habitat, and freshwater availability for municipal and industrial use.
- Click on the station icon to access the following information:
- The station identification number, station name and a link to the National Water Information System (NWIS) station current conditions page data.
- The current CSI 12-month interval value.
- The CSI stacked graph that allows the user to evaluate short (1-month) to long- (24-month) conditions in one graph. Go to the About the CSI tab to learn how to read and interpret the CSI stacked graph.
- A link to all the CSI graphs for that particular gage.
Coastal Salinity Index
(12-month interval CSI values, as of )
- CD4 or less
- CD3 to
- CD2 to
- CD1 to
- CD0 to
- Normal to
- None Not Available
- Coastal Drought (CD)
- Coastal Wet (CW)
- CW0 to
- CW1 to
- CW2 to
- CW3 to
- CW4 or more
South Atlantic CSI Gages
Input Salinity Data (one file for all gages)
Hover mouse over Station Number to identify icon on the map
|Station Number||Station Name||Output CSI Data|
|0208114150||ROANOKE RIVER AT NC 45 NR WESTOVER, NC||0208114150.csv|
|02081094||ROANOKE RIVER AT JAMESVILLE, NC||02081094.csv|
|02110777||AIW AT HIGHWAY 9 AT NIXONS CROSSROADS, SC||02110777.csv|
|02110770||AIW AT GRAND STRAND AIRPORT N. MYRTLE BEACH, SC||02110770.csv|
|02110755||AIW AT BRIARCLIFFE ACRES AT N. MYRTLE BEACH, SC||02110755.csv|
|02110760||AIW @ MYRTLEWOOD GOLF COURSE @ MYRTLE BEACH, SC||02110760.csv|
|02110815||WACCAMAW R NR HAGLEY LAND. NR PAWLEYS ISLAND, SC||02110815.csv|
|02172020||W BRANCH COOPER R @ PIMLICO NR MONCKS CORNER, SC||02172020.csv|
|02172040||BACK RIVER AT DUPONT INTAKE NR KITTREDGE, SC||02172040.csv|
|02172050||COOPER R NR GOOSE CREEK, SC||02172050.csv|
|021720677||COOPER RIVER @ FILBIN CREEK @ NORTH CHARLESTON, SC||0217205677.csv|
|021720698||WANDO RIVER ABOVE MT PLEASANT, SC||021720698.csv|
|021720709||COOPER RIVER AT U.S. HWY 17 AT CHARLESTON, SC||021720709.csv|
|021720710||COOPER RVR @ CUSTOMS HOUSE (AUX) @ CHARLESTON, SC||021720710.csv|
|021989784||L BACK RIVER ABOVE LUCKNOW CANAL, NR LIMEHOUSE, SC||021989784.csv|
|021989791||LITTLE BACK RIVER AT F&W DOCK, NEAR LIMEHOUSE, SC||021989791.csv|
|02198920||SAVANNAH RIVER AT GA 25, AT PORT WENTWORTH, GA||02198920.csv|
The CSI is a standardized probability index. A value of zero indicates historical mean salinity amount, and positive and negative values represent increasingly fresh and saline conditions, respectively. The CSI uses the same classification scheme as the U.S. Drought Monitor for high saline, or drought, conditions (see table 1 on About the CSI tab).
The map on this page shows real-time CSI calculations (12-month interval) for 17 USGS-operated stations in North Carolina, South Carolina, and Georgia. The data used on this site come from the USGS NWIS database. All real-time data are provisional and subject to revision.
Salinity index values are calculated at the end of the day; the displayed values on the map are for the previous day ().
For more information about the development of this index, see About the CSI.
Coastal Salinity Index (CSI) Information
|Coastal Salinity Classification||Description||Threshold Values||Icon||Cumulative Percentage|
|CD4||Exceptional salinity conditions||-2.00 or less||2|
|CD3||Extreme salinity conditions||-1.99 to -1.60||5|
|CD2||Severe salinity conditions||-1.59 to -1.30||10|
|CD1||Moderate salinity conditions||-1.29 to -0.80||20|
|CD0||Abnormal salinity conditions||-0.79 to -0.50||30|
|Normal||Normal salinity conditions||-0.49 to 0.50||70|
|CW0||Abnormal freshwater conditions||0.51 to 0.80||80|
|CW1||Moderate freshwater conditions||0.81 to 1.30||90|
|CW2||Severe freshwater conditions||1.31 to 1.60||95|
|CW3||Extreme freshwater conditions||1.61 to 2.00||98|
|CW4||Exceptional freshwater conditions||2.01 or more||100|
|Not Available||Missing Data|
Questions or problems with the web pages? Contact email@example.com.
Questions concerning CSI? Contact firstname.lastname@example.org.